The present invention relates generally to an improved linkage adapted for operatively connecting buckets and other implements to an arm of an excavator or like apparatus. In particular, the present invention relates to an improved implement linkage for an excavator that is adapted for being adjusted to improve digging efficiency by varying the speed and force characteristics of the linkage as desired depending upon the particular task to be performed. For ease of understanding the invention, it will be described with particular reference to excavators and the connection of a bucket implement to the arm of the excavator. Of course, those of ordinary skill in the art will appreciate that the invention has wider application and provides a speed/force adjustable linkage for connecting any implement to the boom or arm of any apparatus such as a backhoe, tractor, or the like.
Excavators are well known and widely used in various industries. Typically, such excavators include a boom extending from a base of the excavator to an outwardly and upwardly extending distal end, at which end an arm (or xe2x80x9cdipper stickxe2x80x9d) is attached. The arm pivots relative to the boom, and the distal end of the arm is adapted for operative securement of an implement thereto such as a shovel or bucket for removing and depositing earth or the like. Other industries, such as the materials handling industry, employ shears, grapples, magnets, and other such devices at the distal end of the arm. Regardless of the type of implement employed at the end of the arm, it will be understood by those skilled in the art that an excavator employs fluid cylinders and the like for raising and lowering the boom, the arm, for moving the implement relative to the arm, and for operating any mechanisms of the implement, itself.
In a most basic arrangement, the implements are manually pinned to the excavator arm and any associated fluid cylinders by way of a linkage assembly. Such operation necessarily requires manual removal and replacement of multiple pins to achieve the desired engagement. The removal and placement of such pins involves manually and hydraulically manipulating the heavy and cumbersome arm, a fluid cylinder, and/or the implement.
More recently, quick couplings have been developed and have enjoyed widespread commercial success. One suitable coupling is commercially available from JRB Company, Inc., Akron, Ohio under the trademark SLIDE-LOC(copyright). Such quick couplings are pinned to the distal end of the arm and, once in place, are adapted for selective connection to any of a wide variety of implements as desired in a convenient and secure manner. More particularly, these prior quick couplings include mechanisms for selectively mating with and retaining the pins of an associated attachment, often without requiring an operator of the excavator to leave the operator""s cab.
In either case, once the implement is connected to the arm of the excavator or other apparatus, the structural relationship between the implement cylinder and the implement (i.e., the implement linkage), itself, is fixed and may not be varied to change the speed and force characteristics of the linkage arrangement. Thus, with conventional implement linkages, exertion of a select force (F) on the implement link member results in a select amount of the force (X*F) being transferred to the implement, wherein the parameter (X) is fixed and cannot be varied. Likewise, movement of the implement cylinder with a select speed (V) results in movement of the implement, itself, at a speed (Y*V), wherein the parameter (Y) is fixed and cannot be varied. Thus, the speed/force characteristics of the linkage are fixed and are often sub-optimal for a particular task.
In practice, when excavating sand or other soft, easily displaced materials, it is desirable to excavate with more speed; however, less force is required. In contrast, if excavating clay, mud, or other packed, dense materials, more force is required, and speed is of less importance. Therefore, an excavator or other machine with a conventional, fixed implement linkage will be used inefficiently and in a manner that increases expenses for labor and equipment, and that also decreases project efficiency overall. Also, improper speed/force characteristics for a particular excavating or other task can unnecessarily strain fluid cylinders and other components.
In light of the foregoing specifically noted deficiencies and others associated with prior fixed implement linkages, a need has been identified for a new and improved implement linkage for an excavator or like apparatus wherein the speed and force characteristics of the linkage are adjustable by and end-user as desired based upon the task to be performed.
In accordance with the present invention, a novel and non-obvious implement linkage for an excavator, backhoe, or like apparatus is provided wherein the speed and force (speed/force) characteristics of the linkage, and the implement connected thereto, are selectively variable by an end-user depending upon the task to be performed with the implement.
One advantage of the present invention resides in the provision of an implement linkage for an excavator or like apparatus wherein the implement linkage is adjustable by an end-user in the field to vary the speed/force characteristics of the linkage and an implement operatively coupled thereto.
Another advantage of the present invention is found in the provision of a speed/force adjustable implement linkage for an excavator or the like that allows for convenient and rapid speed/force adjustments to be made to the linkage, without disconnecting the associated implement from the linkage.
Still another advantage of the present invention is the provision of a speed/force adjustable implement linkage for an excavator or the like that does not add significant weight to the arm or boom of the excavator or other unit to which the associated implement is connected, and that is usable without requiring any modifications to the bucket or other associated implement to be operatively coupled thereto.
Yet another advantage of the present invention resides in the provision of a speed/force adjustable implement linkage for an excavator or other apparatus that allows the excavator or other apparatus to be used with optimum efficiency.
A further advantage of the present invention is found in the provision of a speed/force adjustable implement linkage that minimizes undue strain on the fluid cylinders that operate the linkage and implement and on the linkage assembly, itself.
Still other benefits and advantages of the present invention will become apparent to those of ordinary skill in the art to which the invention pertains upon reading and understanding the following specification.